Stealth Feature (Radar, Mars)
Regions on Mars showing unusual, extremely low return (nearly zero, or below the 1-sigma noise value) when probed with 3.5- and 12.6-cm Earth-based radar data.
A deposit of unconsolidated, granular fine-grained (<1 cm) dust or ash or other material with a density less than about 0.5 g/cm3, with a minimum thickness of several meters. Radar absorption is caused by a material without any volume scatterers (rocks > few cm). The characteristic of microwave observations suggests it has very low density (Ivanov et al. 1998, 2006). Some parts of the low-return radar units correlate with portions of the Medusae Fossae Formation (MFF) that are large accumulations of fine-grained, friable deposits. Several hypotheses have been proposed about the origin of the material of the MFF that includes ash flow tuffs or ignimbrites, pyroclastic or aeolian materials, paleopolar deposits or loess, carbonate platforms, ice-rich dusty mantling deposited during high obliquity, or ash...
- Bridges NT, Banks ME, Beyer RA, Chuang FC, Noe Dobrea EZ, Herkenhoff KE, Keszthelyi LP, Fuishbaugh KE, McEwen AS, Michaels TI, Thomson BJ, Wray JJ (2010) Aeolian bedforms, yardangs, and indurated surfaces in the Tharsis Montes as seen by the HiRISE camera: evidence for dust aggregates. Icarus 205:165–182CrossRefGoogle Scholar
- Butler BJ (1994) The 3.5-cm radar investigation of Mars and Mercury: planetological implications. PhD dissertation, California Institute of Technology, PasadenaGoogle Scholar
- Butler B, Chizek MR, Slade MA, Haldemann AF, Muhleman DO, Mao TF (2006) Goldstone/VLA 3.5 cm Mars Radar Observations – “Stealths” and South Polar Regions. American Astronomical Society, DPS meeting #38, #67.05; Bulletin of the American Astronomical Society, vol 38, p 619Google Scholar
- Ivanov AB, Safaeinili A, Picardi G, Plaut JJ (2006) Observations of the “stealth” radar feature in the Mars Express MARSIS investigation. Lunar Planet Sci Conf XXXVII, abstract #1946, HoustonGoogle Scholar
- Watters TR, Campbell BA, Carter LM, Leuschen CJ, The MARSIS Science Team et al (2007b) MARSIS subsurface radar sounding of the Medusae Fossae Formation, Mars. Lunar Planet Sci XXXVIII:1661, HoustonGoogle Scholar